title: Determination of 3-α-hydroxytibolone in human plasma by LC-MS/MS: application for a pharmacokinetic study after administration of a tibolone formulation.
abstract: A new method was developed for the quantitation of 3-α-hydroxy tibolone, in human plasma, after oral administration of a tablet formulation containing tibolone (2.5 mg). 3-α-Hydroxy tibolone was extracted by a liquid-liquid procedure, using cyproterone acetate as internal standard and chlorobutane as extraction solvent. After extraction, samples were submitted to a derivatization step with p-toluenesulfonyl isocyanate. A mobile phase consisting of acetonitrile and water (72:28 v/v) was used and chromatographic separation was achieved using Agilent XDB C18 column (100 × 4.6 mm i.d.; 5 µm particle size), at 40°C. Mass spectrometric detection was performed using atmospheric pressure chemical ionization in negative mode for 3-α-hydroxy tibolone and in positive mode for cyproterone acetate. The fragmentation transitions were m/z 510.2 → m/z 170.1 and m/z 417.0 → m/z 357.1 for 3-α-hydroxy tibolone and cyproterone acetate, respectively. Calibration curves were constructed over the range 100-30,000 pg/mL and the method was shown to be specific, precise and accurate, with a mean recovery rate of 94.2% for 3-α-hydroxy tibolone. No matrix effect or carry-over was detected in the samples. The validated method was applied in a pharmacokinetic study with a tibolone formulation in healthy female volunteers.
authors.affiliation: Instituto de Ciências Farmacêuticas, Alameda Coronel Eugênio Jardim 53, 74175-100, Goiânia, GO, Brazil.
authors.forename: Fabiana Fernandes
authors.initials: FF
authors.lastname: de Santana e Silva Cardoso
authors.forename: Isabela Costa
authors.initials: IC
authors.lastname: César
authors.forename: Iram Moreira
authors.initials: IM
authors.lastname: Mundim
authors.forename: Leonardo
authors.initials: L
authors.lastname: de Souza Teixeira
authors.forename: Enikson Pontes
authors.initials: EP
authors.lastname: da Silva
authors.forename: Ricardo Rodrigues
authors.initials: RR
authors.lastname: Bonfim
authors.forename: Sandro Antônio
authors.initials: SA
authors.lastname: Gomes
authors.forename: Denys Pires
authors.initials: DP
authors.lastname: Ferreira
authors.forename: Aderimar Rogério Batista
authors.initials: AR
authors.lastname: Lopes
authors.forename: Helifas Duarte
authors.initials: HD
authors.lastname: Pascoal
authors.forename: Weidson Carlo
authors.initials: WC
authors.lastname: de Souza
authors.forename: Gerson Antônio
authors.initials: GA
authors.lastname: Pianetti
mesh_terms: D000284:Administration, Oral; D002853:Chromatography, Liquid / Q000379:methods*; D020847:Estrogen Receptor Modulators / Q000008:administration & dosage; D005260:Female; D006801:Humans; D057230:Limit of Detection; D009652:Norpregnenes / Q000008:administration & dosage / Q000097:blood*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: C485705:3-hydroxytibolone; D020847:Estrogen Receptor Modulators; D009652:Norpregnenes; C027385:tibolone
keywords: 3-α-hydroxy tibolone; LC-MS/MS; pharmacokinetics; plasma; tibolone